The invention relates to hand tools having sleeves covering their handles. Electricians, carpenters, plumbers or other tradespeople who make repetitive use of the same hand tool are susceptible to having their hands become sore or injured through repetitive use of the tool. For this reason tools are often provided with a sleeve on the handles to provide a more comfortable gripping surface for the user and to reduce the risk of fatigue or injury.
The sleeves have been attached to the handles in a variety of ways. Sometimes adhesives are used. The adhesive is applied to the handle or it is injected into the sleeve before the handle is inserted into the sleeve. It is important not to use too much adhesive otherwise the result is messy. On the other hand, using too little adhesive will fail to adequately secure the sleeve to the handle with the result that one or more of the sleeves may slide off the handle during use. Another method of attaching a sleeve to a handle is an interference fit. The inside surface of the sleeve generally defines a cavity in the shape of the handle but slightly smaller than the handle. The sleeve is made of a resilient material so that it may stretch to the size of the handle and form a tight, high friction engagement around the handle. Since the sleeve cavity is smaller than the handle, it can be difficult to insert fully the handle into the sleeve because each portion of the sleeve must stretch to accommodate the handle as the handle is inserted all the way into the sleeve. On the other hand, if the sleeve cavity is made too large the sleeves may inadvertently slide off the handles during use. Still another technique for providing a sleeve is a hot dip coating process. The handle is dipped in a high temperature bath of liquid coating material which then cools to form a sleeve. While this process positions the sleeve snugly around the handle without stretching difficulties, the resulting material may not provide the desired cushioned feel to the user once the material cools to ambient temperature.
The present invention provides for a tool with sleeve retention which mechanically retains the sleeves on the handles while providing the desired cushioned grip.
The hand tool sleeve retention of the present invention will be described as it would be applied to tools in the nature of pliers or wire strippers. It will be understood that the invention is applicable to a wide variety of hand tools and is not limited to pliers. Pliers are generally comprised of first and second elongated members which are pivotably connected at a joint. Each of the first and second elongated members has first and second jaw portions disposed on one side of the joint and first and second handles disposed on the opposite side of the joint. The first and second handles each have first and second free ends which are located opposite the joint. There is at least one sleeve retaining element disposed near each free end. One type of retaining element comprises a notch although other retaining elements are possible. The first and second handles are inserted into first and second sleeves, respectively. Each sleeve has at least one engaging element formed therein and correspondingly positioned to engage at least one retaining element when the sleeve is placed on the handle. The engaging element may be in the form of a projection or the like.
Where the retaining element is formed as a notch, the notch may be curved about a center which is located within the handle. Barbs are formed on the handle by a convergence of a handle outer surface with the interior or arcuate surface of the notch. In this way, the barbs are disposed at the periphery of the notch and the arcuate extent or circumference of the notch is greater than 180xc2x0 but less than 360xc2x0, with the center of the notch located within the handle.